This invention relates generally to elastomeric door gaskets and more particularly to an elastomeric door gasket for a cold storage door or the like.
In the fabrication of doors for environmental enclosures such as freezers, cold storage lockers and coolers, an airtight seal between the door and the door frame of the environmental enclosure is desirable so that the temperature of the environmental enclosure interior can be maintained substantially constant. To achieve a substantially airtight seal between the cold storage door and the door frame, an elastomeric gasket is usually mounted to either the door frame or to the door so that the gasket abuts the door or door frame, respectively, to eliminate any void between the door and door frame.
Present day elastomeric door gaskets for cold storage doors generally include a gasket base which is affixed either to the jamb of the door frame or to the outer edge of the door. A strip of elastomeric gasket material has a separate one of its lateral edges fastened at opposite edges of the gasket base so that the gasket strip is deformed in the shape of a half-rounded body. It is this half-rounded body which is deformed when the door is brought into contact with the door jamb upon closing to provide a seal between the door and door frame. To impart rigidity to this deformable gasket strip body, a foam rubber tube or the like is inserted into the void between the gasket strip and the gasket base.
In the past, two different types of cold storage door gasket constructions have been utilized. One type of prior art cold storage door gasket includes a gasket base which takes the form of a web having a pair of oppositely disposed, upstanding flanges. The elastomeric gasket strip is secured by adhesive at each of its lateral edges to one of the two depending flanges of a gasket channel which is then pressed between the flanges of the gasket base, thereby wedging the gasket strip between the flanges of the gasket base and the gasket channel. Mechanical fasteners, such as self tapping screws, extend through the flanges of the gasket base and gasket channel to secure the gasket channel to the gasket base.
Another type of prior art cold storage door gasket employs a gasket base having a pair of spaced apart upwardly rising channels running along the length of the gasket base. The lateral edges of the strip of gasket material, each carry a bead which is dimensioned to be slidably received within a separate one of the channels of the gasket base. In this way, the elastomeric gasket strip is retained in the gasket base.
Regardless of which type of prior art gasket construction is utilized with a cold storage door, repeated closing of the cold storage door, and the resultant deformation of the half-rounded gasket strip body usually results in significant wear of the gasket strip. Eventually, replacement of the gasket strip of the door gasket becomes necessary. To facilitate replacement of the elastomeric gasket strip of first described type of prior art door gasket, the mechanical fasteners which secure the gasket channel to the gasket base must be removed. Only after the mechanical fasteners have been removed can the gasket strip be separated from the gasket channel to allow a new gasket strip to be installed. With the other type of prior art door gasket, the gasket strip must be completely slid from the gasket base so that each of the beads on the lateral gasket edges no longer engage the gasket channels. Once this is completed, a new strip of gasket material can be installed.
Irrespective of which of the two above-described types of prior art door gaskets are installed on a cold storage door, replacement of the door gasket strip is generally difficult and time consuming. In particular, replacement of the gasket strip of either type of prior art cold storage gasket becomes very difficult when the gasket is mounted at the base of the cold storage door. Oftentimes, there may be insufficient clearance to allow removal of any mechanical fasteners or sliding of the gasket strip.
Another problem associated with prior art cold storage door gaskets is the manner in which the gasket strip is heated to keep it supple at low temperatures. In the past, the gasket strip of prior art cold storage door gaskets has been heated by an electric strip heater which is mounted either on the door or on the jamb of the door frame to abut the gasket strip when the door is closed. While the prior art gasket strip heaters accomplish gasket strip heating they do so only when the door is closed. Moreover, the external heating of the gasket strip by prior art gasket heaters results in considerable heat loss to the atmosphere. Such heat loss results in wasted energy and hence higher operating costs for the cold storage door.
In contrast to the prior art door gaskets, the present invention concerns an improved door gasket whose elastomeric strip member may be readily replaced without the need to slide the gasket strip from the gasket base or to remove any separate mechanical fasteners securing the gasket base to the gasket channel. Moreover, the improved door gasket of the present invention is provided with a heater disposed interior of the half-rounded elastomeric gasket strip body created when the lateral edges of the gasket strip are secured to the gasket base. The location of the heater within the gasket strip body void assures efficient gasket strip heating.